Flux pinning for in situ Nb/sub 3/Sn superconducting wire

Journal Article · Mon Aug 01 04:00:00 EDT 1983 · Acta Metall.; (United States)

DOI:https://doi.org/10.1016/0001-6160(83)90185-2· OSTI ID:5476865

Verhoeven, J D; Finnemore, D K; Gibson, E D; Ostenson, J E; Sue, J J

Critical currents and upper critical fields have been evaluated for in situ prepared Nb/sub 3/Sn-Cu multifilamentary superconducting wire in order to determine which aspects of filament morphology are most important for flux pinning. Wire specimens were prepared with a wide range of Nb/sub 3/Sn filament sizes as controlled by the as-cast dendrite size, the degree of wire drawing and the degree of filament coarsening. Tape specimens were examined as a function of orientation in the magnetic field. The Nb/sub 3/Sn filament and grain morphology were examined with SEM and TEM techniques. In all cases the pinning force was found to follow an h* /SUP 1/2/ (1-h*)/sup 2/ dependence where h* is the reduced magnetic field, H/H* /SUB c2/ and the data consistently yielded parallel lines on a Kramer plot. Neither the perfect lattice shear model of Kramer nor the surface pinning model of Dew-Hughes adequately describe in situ data. Analysis of the critical current results and the Nb/sub 3/Sn filament and grain morphology indicates that flux pinning in thes in situ materials is not dominated by either the Nb/sub 3/Sn/Bronze interfaces or the Nb/sub 3/Sn grain boundaries, but is probably due to a combination of pinning at both interfaces.

• Research Organization: Ames Laboratory, USDOE, Department of Materials Science and Engineering, and Department of Physics, Iowa State University, Ames, IA 50011
• OSTI ID: 5476865
• Journal Information: Acta Metall.; (United States), Journal Name: Acta Metall.; (United States) Vol. 31:8; ISSN AMETA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360102* -- Metals & Alloys-- Structure & Phase Studies
360104 -- Metals & Alloys-- Physical Properties
ALLOYS
BRONZE
COPPER
COPPER ALLOYS
COPPER BASE ALLOYS
CRITICAL CURRENT
CRITICAL FIELD
CRYSTAL STRUCTURE
CRYSTALS
CURRENTS
DENDRITES
ELECTRIC CONDUCTIVITY
ELECTRIC CURRENTS
ELECTRICAL PROPERTIES
ELECTRON MICROSCOPY
ELEMENTS
GRAIN BOUNDARIES
INTERFACES
MAGNETIC FIELDS
MAGNETIC FLUX
METALS
MICROSCOPY
MICROSTRUCTURE
MORPHOLOGY
NIOBIUM ALLOYS
PHYSICAL PROPERTIES
SCANNING ELECTRON MICROSCOPY
SUPERCONDUCTIVITY
TIN ALLOYS
TRANSITION ELEMENTS
TRANSMISSION ELECTRON MICROSCOPY
WIRES